Once They Offer You the Job
This is the one and only moment until you have an evaluation where you have any negotiating power. Use it wisely and reasonably. In the research phase you should have found out what the going rate is for this position. Your salary requirements should of course be based on the going rate, as well as your needs.
However, when you communicate with the employer you should speak solely of your unique skills and how that makes you a more valuable employee. Believe me they don't care how much your rent is. Consider benefits when you evaluate your wage and it is acceptable to send a reasonable counter offer. Decide ahead of time on what you will accept and what you think your skills are worth, also considering your other values I spoke of earlier. Then decide to accept or decline the position based on that criteria.
Hopefully, you will have several other options as you did not apply for just one position. This leaves you in a comfortable position to negotiate while retaining personal standards.
